To provide information which is easily recognizable by a user about the congestion continuing long or short in distance.

A navigation ECU 14 decides whether the congestion distance extracted from congestion information received by a VICS receiver 11 is exceeds a reference value Lm designated by a user operating a operation switch group 6 (S10). If the congestion distance is less than Lm (S10: NO), it leaves the congested place in a normal display mode (S20), but if Lm is exceeded (S10: YES), executes a blinking indication of the congested place (S30). It repeats these steps of process, until all roads to be indicated have been checked. Such control is executed, if the congestion distance is long, to attract the user's attention and prompt the user to earlier take measures, such as detouring.